Magnetic-resistant watch case

ABSTRACT

A magnetic-resistant watch case assembly comprising a dial support and a casing-ring both made of a high-permeability material and surrounding a watch movement to position and fix the watch movement in the watch case.

United States Patent 1191 Nishizawa Nov. 18, 1975 MAGNETIC-RESISTANTWATCH CASE [56] References Cited [75] Inventor: Akio Nishizawa, Okaya,Japan UNITED STATES PATENTS [73] Assignee: Kabushiki Kaisha SuwaSeikosha, 1247470 11/ 1917 Turney .5 58/1065 Tokyo, Japan PrimaryE.\'amz'nerGeorge H. Miller, Jr. [22] Ffled' 1974 Attorney, Agent, orFirm-Waters, Schwartz & Nissen [21] Appl. No.: 515,032

[57] ABSTRACT [30] Forelgn Apphcauo Pnomy Data A magnetic-resistantwatch case assembly comprising Oct. 16 1973 Japan .4 48-115321 a dialsup ort and a casing-ring both made of a high-permeability material andsurrounding a watch [52] US. Cl 58/ 106.5; 58/94 ve nt to po ition andfix the watch movement in [51] Int. CLZ G04B 43/00; 60413 37/04 thewatch case, [58] Field of Search 58/94, 106.5

9 Claims, 8 Drawing Figures ,1 I I I x r f l 1/ .[LJ/l/J/J/I US. PatentNov. 18, 1975 Sheet10f4 3,919,836

US. Patent Nov. 18,1975 Sheet30f4 3,919,836

US. Patent Nov. 18, 1975 Sheet40f4 3,919,836

FIG 7 MAGNETIC-RESISTANT WATCH CASE FIELD OF THE INVENTION Thisinvention relates to a magnetic-resistant watch case which has highmagnetic-resistance and low cost.

BACKGROUND In electric or electronic timepieces, a high-permeabilitymaterial is sometimes provided inside its case and around its movementto improve its magnetic-resistance. In a. timepiece driven by amainspring, similar provision may be taken if the magnetic-resistancemust be particularly improved. Conventional magneticresistant watchcases used in such cases are not suitable because theirmagnetic-resistant effect is relativelylow and their price is high.

SUMMARY OF THE INVENTION According to the invention, a watch caseassembly is provided which comprises a case structure, a watch movementdisposed in said case structure, a dial support covering said movementon one side thereof, and a casing ring covering the movement at theother side thereof, said dial support and casing ring both being made ofhigh permeability material and cooperatively surrounding said watchmovement and including means positioning and securing the watch.movement in the case structure.

At least one of the dial support and casing ring includes an integralcylindrical portion laterally encircling the watch movement andprojecting towards the other.

In a particular embodiment both said dial support and casing ringinclude respective cylindrical portions projecting towards one anotherand lateral rim portions are provided on said cylindrical portions atthe ends thereof.

The watch movement can have steps formed therein at its top and bottomperipheral portions and the dial support and casing ring can be seatedin said steps to secure and position the watch movement.

BRIEF DESCRIPTION OF THE DRAWING FIG. 1 is a vertical section showing aportion of a conventional watch,

FIG. 2 is a vertical section showing a corresponding portion of anembodiment according to the invention, and

FIGS. 3 to 8 are vertical sections of other embodiments of theinvention.

DETAILED DESCRIPTION OF DRAWING Referring to FIG. 1 which shows anembodiment of a conventional magnetic-resistant structure, thereinhigh-permeability material is used at three places, i.e. at a plate 1below a dial, a casing-ring 2 and a back plate 3. The plate 1 is heldbetween a dial 4 and a ring 5 for supporting the dial. The casing-ring 2is inserted between a movement 6 and a case band 7 to center themovement as well as to fix the movement with the use of upward force ofa back cover 8. The back plate 3 is fixed to the inner surface of theback cover 8.

Such a conventional magnetic-resistant watch structure is high in costbecause the high-permeability material is distributed to three membersand the casing-ring requires a pressing process and a cutting process.Furthermore, the magnetic-resistance of such structure is not sufficientbecause the members constituted of the high-permeability material havewide gaps therebetween, and thereby the movement is readily influencedby an external magnetic field.

This invention eliminates the above defects and will be described withreference to the embodiment shown in FIG. 2.

Therein a dial support 9 is formed of a plate member ofhigh-permeability material by means of a drawing press to include a discportion 9a, a depending cylindrical portion 9b and a rim portion 9c. Thesupport 9 covers the upper portion of a movement 10. Similarly, a

casing-ring 11 is formed of a plate member of highpermeability materialby means of a drawing press to include a disc portion 11a, a cylindricalportion 11b and a rim portion 11c. The ring 11 covers the lower portionof the movement 10.

The movement 10 is provided with recesses defining shoulders 10a and 10bat its periphery at positions corresponding to the cylindrical portionsand the rim portions of the dial support and the casing-ringrespectively. The movement is held between the rim portions of the dialsupport and the casing-ring. The rim portions are held between an uppercylindrical portion 12a of a back cover 12 and a shoulder 13a of aninner step portion of a case band 13 by the upward force of the backcover. Thus the movement is fixed. A dial 14 is fixed to the movement sothat the dial support is sandwiched therebetween.

According to this invention, only two members are made ofhigh-permeability material and only the two members require the use of adrawing press. Accordingly, the cost price is reduced. Furthermore, themembers of high-permeability material which cover the movement have onlya relatively small gap therebetween and the movement is notsubstantially influenced by an external magnetic field. Thus, theinvention provides an excellent magnetic-resistant watch case.

In FIG. 3, a depending cylindrical lip portion 9d is provided at theperiphery of the rim 9c of the dial support 9. In this structure, thehigh-permeability members covering the movement have substantially nogap. The magnetic-resistance of the watch case is even greater thereby.

In FIG. 4, an upward cylindrical lip portion 11d is provided at theperiphery of the rim 110 of the casingring 11 to achieve the same effectas in FIG. 3.

As shown in FIG. 5, if the watch is designed so that the dial support 9and the casing-ring l 1 have the same shape and size, both members canbe interchangeable and can be manufactured in equivalent manner so thatthe cost price is further reduced.

In FIG. 6, the casing-ring 11 is provided with openings lle and 11f atpositions corresponding to projected portions and 10d of the movement10. In this case, the height of the cylindrical portion 11b of thecasing-ring can be reduced so that the total thickness of the watch casecan be reduced. Additionally, the highpermeability member may be locallythickened or thinned as shown at the rim 9c of the dial support 9, forthe purpose of providing increased strength or the like.

As shown in FIG. 7, if a shock-absorbent member 15 is provided betweenthe rim 11c of the casing-ring 11 and the upper cylindrical portion 12aof the back cover 12, variation of interference of a gasket 16 of theback cover can be reduced as much as possible because theshock-absorbent member 15 absorbs various kinds of size variation of themembers which fix the movement As shown in FIG. 8, the same effect as inFIG. 7 can beobtained by disposing the shock-absorbent member 15 betweena peripheral stepped portion lb of the movement 10 and an uppercylindrical portion 11g of the casing-ring 11, with the cylindricalportion 11b of the casing ring 11 being further stepped to form theupper cylindrical portion 11g. The same effect is obtained even if thedial support 9 is not provided with the cylindrical portion nor the rimportion as in the previous embodiments.

The construction according to this invention improves themagnetic-resistance of a watch case and reduces its cost price and it isvery effective in practice applicable to all sizes and shapes ofwatches. 3

What is claimed is:,

l. A magnetic-resistant watch case assembly comprising a case structure,a watch movement disposed in said case structure, a dial supportcovering said movement at one side thereof, and a casing-ring coveringthe movement at the other side thereof, said dial support andcasing-ring both being made of high-permeability material andcooperatively surrounding said watch movement, at least one of the dialsupport and casingring including an integral cylindrical portionlaterally encircling the watch movement and projecting towards theother, and a lateral rim portion on said cylindrical portion at the endthereof, said watch movement having a step therein, said cylindricalportion and rim portion being seated in said step to position and securethe watch movement in the case structure.

2. An assembly as claimed in claim 1, wherein both said dialsupport andcasing-ring include respective cylindrical portions projecting towardsone another and lateral rim portions on said cylindrical portions at theends thereof.

3. An assembly as claimed in claim 2 wherein said watch movement has aplurality of steps therein, said cylindrical portion and rim portion ofthe dial support and the casing-ring being seated in respective of saidsteps.

4. An assembly as claimed in claim 3, wherein one of said dial supportand casing-ring includes a cylindrical lip portion on the rim portionthereof, said lip portion encircling the watch movement in the regionbetween the rim portions of the dial support and casing ring.

5. An assembly as claimed in claim 3, wherein at least one of said dialsupport and casing-ring includes a local portion of different thicknessfrom the remainder thereof.

6. An assembly as claimed in claim 3, wherein at least one of said dialsupport and casing-ring has an aperture to accommodate a projectionprovided on said watch movement.

7. An assembly as claimed in claim 3, further comprising a back plateand a shock-absorbing member engaged between said back plate and saidcasing-ring.

8. An assembly as claimed in claim 3, further comprising ashock-absorbing member engaged between said casing-ring and said watchmovement.

9. An assembly as claimed in claim 3, wherein said dial support andcasing-ring are symmetrical and interchangeable.

1. A magnetic-resistant watch case assembly comprising a case structure,a watch mOvement disposed in said case structure, a dial supportcovering said movement at one side thereof, and a casing-ring coveringthe movement at the other side thereof, said dial support andcasing-ring both being made of high-permeability material andcooperatively surrounding said watch movement, at least one of the dialsupport and casing-ring including an integral cylindrical portionlaterally encircling the watch movement and projecting towards theother, and a lateral rim portion on said cylindrical portion at the endthereof, said watch movement having a step therein, said cylindricalportion and rim portion being seated in said step to position and securethe watch movement in the case structure.
 2. An assembly as claimed inclaim 1, wherein both said dial support and casing-ring includerespective cylindrical portions projecting towards one another andlateral rim portions on said cylindrical portions at the ends thereof.3. An assembly as claimed in claim 2 wherein said watch movement has aplurality of steps therein, said cylindrical portion and rim portion ofthe dial support and the casing-ring being seated in respective of saidsteps.
 4. An assembly as claimed in claim 3, wherein one of said dialsupport and casing-ring includes a cylindrical lip portion on the rimportion thereof, said lip portion encircling the watch movement in theregion between the rim portions of the dial support and casing ring. 5.An assembly as claimed in claim 3, wherein at least one of said dialsupport and casing-ring includes a local portion of different thicknessfrom the remainder thereof.
 6. An assembly as claimed in claim 3,wherein at least one of said dial support and casing-ring has anaperture to accommodate a projection provided on said watch movement. 7.An assembly as claimed in claim 3, further comprising a back plate and ashock-absorbing member engaged between said back plate and saidcasing-ring.
 8. An assembly as claimed in claim 3, further comprising ashock-absorbing member engaged between said casing-ring and said watchmovement.
 9. An assembly as claimed in claim 3, wherein said dialsupport and casing-ring are symmetrical and interchangeable.